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02-8
4. CHECK AND INSPECTION
1) Cylinder
(1) Compression pressure test
Specified value ▶
Compression ratio16.5 : 1
Test conditionat normal operating temperature (80˚C)
Compression
pressureStandard32 bar
Minimum18 bar
Differential limit between cylindersMaximum 3 bar
The compression pressure test is to check the conditions of internal components (piston, piston ring,
intake and exhaust vale, cylinder head gasket). This test provides current engine operating status.
Measurement ▶
Warm the engine up to normal operating temperature (80°C).
Disconnect the fuel rail pressure sensor connector to cut off the fuel injection.
Remove the air cleaner duct and glow plugs. -
-
-
Place the diagram sheet to compression
pressure tester and install it into the plug
hole. 1. Before cranking the engine, make sure that the test wiring, tools and persons are keeping away
from moving components of engine (e.g., belt and cooling fan).
Park the vehicle on the level ground and apply the parking brake.
Do not allow anybody to be in front of the vehicle. -
-
-
Page 228 of 796
03-212210-01
1. OVERVIEW
The components in fuel system supply the fuel and generate the high pressure to inject the fuel to
each injector. They are controlled by the engine ECU.
The common rail fuel injection system consists of fuel tank, fuel line, low pressure line which supplies
low pressure fuel to the low pressure pump (including high pressure pump), common rail which
distributes and accumulates the high pressurized fuel from the fuel pump, high pressure line which
connected to the injector, and the engine control unit (ECU) which calculates the accelerator pedal
position and controls the overall performance of vehicle based on the input signals from various
sensors.
1) Fuel Flow Diagram
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03-24
2) Fuel System Flow Diagram
The fuel from the fuel tank is supplied to the fuel heater of fuel filter/priming pump and then low
pressure generated by the low pressure pump (built into HP pump) is transmitted to the HP pump.
The fuel pressure at the HP pump is controlled by the IMV valve, and the maximum allowed pressure
is 1,800 bar. The compressed fuel at the fuel pump is delivered to the rail, and injected by the injectors
according to the injection signals. The injection method is the same with the conventional method; Fuel
return by backleak which operates the needle valve.
The major difference is that the fuel return line is connected to the fuel filter inlet port, not the HP pump
venturi.
The pressure from the high pressure pump is increased to 1,800 bar from 1,600 bar, and the pump is
now installed to the cylinder head (cylinder block for previous model). The fuel pressure is generated
by the operation of intake camshaft and gears. The specifications for the IMV valve and the fuel
temperature sensor are not changed.
Page 289 of 796
09-131451-01
3. CIRCUIT DIAGRAM
Page 292 of 796
10-51413-00
2. SYSTEM OPERATION
1) Input/Output Diagram of Glow Plug Control Unit
2) System Diagram
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Page 301 of 796
Page 313 of 796
13-6
2. OPERATING PROCESS
1) Schematic Diagram